Buprenorphine and Selpercatinib: Interaction Details
AI-assisted, pharmacist-reviewed · AI content regenerated Jul 11, 2026 · Source data updated Jul 2, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Buprenorphine
Selpercatinib
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
Both buprenorphine (a pain and addiction medicine) and selpercatinib (a cancer medicine) can affect your heart's electrical timing, something called the QT interval. When two medicines that do this are taken together, the effect can add up and, in rare cases, lead to an irregular heartbeat.
The good news is that this concern is based mostly on how the drugs work in theory, not on a lot of real-world problems. Your care team can manage it safely by checking your heart rhythm (an EKG) and your blood minerals like potassium and magnesium. Please keep taking both medicines as prescribed and ask your pharmacist or doctor if you have questions.
Effect: Additive QTc prolongation from concomitant buprenorphine and selpercatinib. Both agents are independently associated with QT prolongation; this is a pharmacodynamic (additive), not pharmacokinetic, interaction. Neither is acting as a prodrug here.
- Severity/onset: Major; onset unspecified. Evidence is theoretical.
- Monitoring: Baseline and periodic ECG, electrolytes (K, Mg, Ca), and TSH; increase frequency with added risk factors such as diarrhea.
- Management: Correct hypokalemia, hypomagnesemia, and hypocalcemia before and during therapy. Per labeling, selpercatinib may be withheld, dose-reduced, or discontinued based on QTc severity, individualized by the oncology team.
What happens
Increased risk of QT interval prolongation
Interaction Deep Dive
When agents known to lengthen the QT interval are taken alongside selpercatinib, their effect may compound the QTc prolongation caused by selpercatinib itself. Measure the QT interval, electrolyte levels, and TSH before starting therapy and at intervals throughout treatment, tailoring how often based on risk factors such as diarrhea. Any hypokalemia, hypomagnesemia, and hypocalcemia should be corrected both before beginning selpercatinib and while it is being administered. Depending on severity, selpercatinib should be withheld and either dose reduced or stopped altogether1.
Why it happens (mechanism)
Additive QT interval prolongation
How to manage this interaction
This interaction is usually manageable with monitoring. Your care team may do the following:
- Check an ECG and blood levels of potassium, magnesium, calcium, and TSH before starting and periodically during treatment.
- Correct any low electrolytes, since these raise the risk.
- Watch you more closely if you develop risk factors like diarrhea.
- Individualize the selpercatinib dose (possibly holding or adjusting it) based on your heart rhythm.
Keep taking both medicines as prescribed. Tell your pharmacist or doctor about any fainting, dizziness, palpitations, or a fast or irregular heartbeat, and mention all other medicines you take.
Management is individual — confirm any change with your pharmacist or prescriber.
Common questions
Can I take Buprenorphine and Selpercatinib together?
Buprenorphine and selpercatinib can each prolong the QT interval, so together the effect may add up; this is manageable with ECG and electrolyte monitoring, so keep taking both as prescribed and report any palpitations or fainting. Always confirm with your pharmacist or prescriber before making any change.
How serious is the Buprenorphine and Selpercatinib interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How is the Buprenorphine and Selpercatinib interaction managed?
This interaction is usually manageable with monitoring. Your care team may do the following: Check an ECG and blood levels of potassium, magnesium, calcium, and TSH before starting and periodically during treatment. Correct any low electrolytes, since these raise the risk. Watch you more closely if you develop risk factors like diarrhea. Individualize the selpercatinib dose (possibly holding or ad… Management is individual — always follow your own care team's guidance.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Buprenorphine or Selpercatinib need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (1)
- Product Information: RETEVMO(R) oral capsules, tablets, selpercatinib oral capsules, tablets. Lilly USA LLC (per FDA), Indianapolis, IN, 2024. DailyMed
Keep reading about Buprenorphine
Keep reading about Selpercatinib
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
Check another combination
Our instant two-drug interaction checker is almost here.
Still have questions about this combination?
Every question gets a real answer from a licensed pharmacist — free, and usually within a day.
Ask the pharmacist